Volkmann, et al. U.S. Pat. No. 2,755,194 teaches the preparation of polydiorganosiloxane emulsions by milling together a polyethylene glycol trimethylmonoether, and alkylaryl polyether sulfate sodium salt, water, and a siloxane polymer which can have various functionalities. This present invention does not teach an emulsification method but aims to teach a method to control the functionality of emulsion compositions.
Findlay and Weyenberg U.S. Pat. No. 3,294,725 teaches a stable polydiorganosiloxane emulsion prepared by polymerizing R.sub.n SiO.sub.(4-2)/2 or HOR.sub.2 SiQSiR.sub.2 OH (where R is hydrogen hydrocarbon, or halohydrocarbon, n is preferably 2, and Q is a divalent hydrocarbon or ether containing hydrocarbon radical) in aqueous medium using a surface active sulfonic acid catalyst such as C.sub.12 H.sub.25 C.sub.6 H.sub.4 SO.sub.3 H. In particular, Example 3 of the '725 patent teaches the use of hexamethyldisiloxane to produce a trimethyl endcapped polymer. However, the '725 patent teaches only modification of the chain end during polymerization while the method of this invention teaches the post modification of a polydiorganosiloxane emulsion.
Schoenherr U.S. Pat. No. 4,618,642, teaches an aqueous silicone elastomeric emulsion that is obtained by mixing an anionic emulsion containing dispersed particles of hydroxyl endblocked polydiorganosiloxane, dialkyltindicarboxylate, silanes of the formula RSi(OR').sub.3 where R is a monovalent hydrocarbon radical of from 1 to 4 carbon atoms inclusive and R' is a lower alkyl radical of from 1 to 4 carbon atoms inclusive or a radical of the formula -N.dbd.CR.sub.2 and inert, non-siliceous filler. Unlike the '642 patent, the present invention does not teach the use of R'Si(OR').sub.3 in the composition.
Kondo et al. U.S. Pat. No. 4,782,112 teaches a mixture of (A) a silicone water-based emulsion composed of water, emulsifying agent, and diorganopolysiloxane having at least 2 silicone-bonded hydroxyl groups in each molecule, (B) a silicone water-based emulsion composed of water, emulsifying agent, and organohydrogen-polysiloxane having at least 2 silicon-bonded hydrogen atoms in each molecule, and (C) a curing catalyst. It is characterized by an excellent storage stability, and by the formation on curing of a rubbery elastomeric coating film which has an excellent alkali resistance, water repellency, water-repellant sealability, and durability of adhesion. The '112 patent, however, does not teach the addition of a functionalizing silane to the polysiloxane as does the present invention.
Liles U.S. Pat. No. 4,954,565 teaches a shelf stable aqueous silicone emulsion which yields an elastomer upon removal of the water, produced by combining a hydroxy endblocked polydiorganosiloxane present as an emulsion of dispersed particles in water, a crosslinker, and a tin catalyst, the tin catalyst being in the form of a divalent tin atom combined with organic radicals. The emulsion, after crosslinking of the polydiorganosiloxane, can be reinforced with colloidal silica without affecting the shelf life of the reinforced emulsion. The '565 patent, however, differs from the present invention because the composition of the '565 patent does not include a monoalkoxy functionalizing silane. Moreover, the '565 patent does not teach adding monohydrolyzable silanes to silanol functional polymers to form non-crosslinked polymers.